[jdx]

Summary

• add a versioned JSON report for Rust action-cache session activity, bytes, request counts, and phase timings
• measure manifest/action lookups, individual blob transfers, local CAS writes, prefetch, and output materialization
• report restored files/bytes and compiler invocations avoided
• preserve the existing summary while adding a concise human-readable timing line

Configuration

Set task.cache.stats_report or MISE_TASK_CACHE_STATS_REPORT to the report path. Timing values are nanoseconds; concurrent phase values are cumulative work and may exceed the end-to-end session duration.

The current client still fetches blobs individually, so the schema intentionally reports remote_blob_requests and blob-transfer time. This gives follow-up packed-transfer work a measurable baseline without claiming a protocol path that is not in use.

Validation

• mise run lint-fix
• cargo test --locked -p mise-cache-core --no-fail-fast
• cargo test --locked --bin mise cache::session --no-fail-fast
• cargo clippy --locked -p mise-cache-core --all-features --all-targets -- -D warnings
• cargo clippy --locked --bin mise --all-features -- -D warnings
• mise run test:e2e e2e/tasks/test_task_rust_cache_restore
• mise run render:schema

AI-assisted — Tool: Codex; model: unavailable/unavailable; version: unavailable.

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Note

Low Risk
Additive metrics and optional file output; agent protocol gains required restore fields on hit/verification requests, which must stay in sync with rustc shims in the same release.

Overview
Adds observability for Rust action-cache sessions: phase timings, remote request counts, restored output volume, and an optional versioned JSON report for CI/benchmarking.

Instrumentation extends the cache agent with RestoreStats on hit/verification records so the rustc adapter reports materialization time and restored file/byte counts. Remote manifest/action lookups, per-blob transfers, local CAS writes, and prefetch runs are timed and counted via AtomicDurationTimer and new AgentStats fields. Session end-to-end duration is set when the cache session finishes.

User-facing output: task.cache.stats_report / MISE_TASK_CACHE_STATS_REPORT writes a v1 JSON report atomically after mise run; the stderr summary gains a second line with cumulative phase timings (nanoseconds). Schema and settings document the new option; e2e restore test asserts the report shape.

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Summary by CodeRabbit

• New Features

  • Added optional action-cache session statistics reports in versioned JSON format.
  • Reports include cache hits and misses, avoided compiler work, data transfers, restored outputs, file and byte counts, and operation timing.
  • Reports are written atomically to the configured path, with parent directories created automatically.
  • Added configuration through task.cache.stats_report or MISE_TASK_CACHE_STATS_REPORT.

• Improvements

  • Cache restoration and remote operations now provide more detailed performance metrics.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Central YAML (inherited), Organization UI (inherited)

Review profile: CHILL

Plan: Pro Plus

Run ID: ab4c97ed-3aa7-4959-ab72-a7441bcb467a

📥 Commits

Reviewing files that changed from the base of the PR and between 4b36fd6 and 984a1c1.

📒 Files selected for processing (1)

• crates/mise-cache-core/src/agent.rs

🚧 Files skipped from review as they are similar to previous changes (1)

• crates/mise-cache-core/src/agent.rs

Included review availability: Your plan includes up to 10 reviews per rolling hour; 8 remain after this review.

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📝 Walkthrough

Walkthrough

The cache agent now records restoration, remote-transfer, prefetch, CAS, and timing metrics. Cache sessions can write versioned JSON reports through the new task.cache.stats_report setting. Rust cache restoration forwards output and materialization statistics.

Changes

Cache statistics

Layer / File(s)	Summary
Agent metrics and request contracts crates/mise-cache-core/src/agent.rs, crates/mise-cache-core/src/lib.rs	Adds RestoreStats, expands AgentStats, instruments cache operations, and records restoration aggregates.
Restore metric propagation src/cache/rustc.rs	Measures restored files, bytes, and materialization time. Forwards these values for action hits and verification.
Session report configuration and output src/cache/session.rs, schema/mise.json, settings.toml, e2e/tasks/test_task_rust_cache_restore	Adds session timing, versioned JSON report generation, atomic writes, configuration, and end-to-end validation.

Estimated code review effort: 4 (Complex) | ~45 minutes

Merge Risk: ⚪ Minimal · up to 984a1

The change is merge-ready after normal checks and review; no actionable merge-blocking risk remains.

Possibly related PRs

• jdx/mise#11328: Implements local artifact-cache restores that this PR measures.
• jdx/mise#11817: Introduces Rust cache restoration and action-hit paths extended by these metrics.
• jdx/mise#11932: Modifies Rust cache output materialization paths instrumented by this PR.

Poem

A rabbit counts each cached byte,
And times the blobs that hop in flight.
Restored files join the report,
Atomic paths keep data short.
“Hop!” says the cache, with metrics bright.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 16.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: reporting action-cache phase timings.

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[greptile-apps]

Greptile Summary

This PR adds a versioned action-cache statistics report with request counts, transfer volumes, restored-output metrics, and phase timings while retaining the existing console summary.

• Instruments remote manifest and action lookups, blob transfers, local CAS writes, prefetch runs, and output materialization.
• Adds task.cache.stats_report and MISE_TASK_CACHE_STATS_REPORT configuration.
• Correctly excludes qualification-only staged outputs from restored file and byte totals.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains; the previously reported qualification-accounting issue is fixed because verification records materialization timing without adding staged outputs to restored file or byte totals.

Important Files Changed

Filename	Overview
crates/mise-cache-core/src/agent.rs	Adds atomic phase metrics and restore accounting; verification now records only materialization duration, so the previously reported restored-output inflation is fixed.
src/cache/rustc.rs	Measures cached-output materialization and distinguishes persisted cache hits from qualification-only staging.
src/cache/session.rs	Tracks session duration, emits the versioned JSON report atomically, and adds concise timing output.
settings.toml	Defines the optional statistics-report path and documents timing semantics.
e2e/tasks/test_task_rust_cache_restore	Extends cache restoration coverage to validate the generated report and its key counters.

_{Reviews (2): Last reviewed commit: "fix(cache): exclude verified outputs fro..." | Re-trigger Greptile}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[github-actions]

Instruction counts

Nothing was compared, and so nothing was gated. No series appears on both sides: either the base has no measurements recorded, or the two were measured on different runner classes, which are deliberately not comparable — counts shift between machine types by more than a real regression does.

New, nothing to compare against: env on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1, hook-env on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1, ls on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1, registry on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1, startup on bamboo-v2-ubuntu24.04-x64-30vcpu-24gb-rust1.97.1

_{Only instruction counts gate. Wall clock is shown for context — on identical hardware it moves 4-20% run to run.}

_{Measured by tak — instruction-counted CLI benchmarks, stored in this repository's git notes.}

_{984a1c11625b vs 6bb08b5d701d · measured on the runner, not pushed to the history.}